Datasheet

TEMPERATURE (
o
C)
PHASE NOISE DEGRADATION
(
dB)
-1
0
1
2
3
-40 -20 0 20
-2
-3
80 10040 60
25
o
C
10 MHz
10 kHz
20 MHz
1 MHz
100 kHz
LMX2541SQ2060E, LMX2541SQ2380E
LMX2541SQ2690E, LMX2541SQ3030E
LMX2541SQ3320E, LMX2541SQ3740E
www.ti.com SNOSB31I –JULY 2009–REVISED FEBRUARY 2013
Typical Performance Characteristics (Not Guaranteed) (continued)
VCO Phase Noise Degradation
vs.
Temperature and Offset
(VCO Relocked at Each Temperature
Vcc = 3.3 V, AC_TEMP_COMP = 5)
The above plot shows how much the VCO phase noise typically change over temperature relative to room temperature. The typical values for
represent an average over all frequencies and part options and therefore there are some small variations over part options and frequencies
that are not shown. VCO phase noise numbers room temperature are reported in the electrical specifications. A negative value indicates a
phase noise improvement.
Figure 12.
Table 1. Relative VCO Phase Noise Over Temperature Drift
(AC_TEMP_COMP = 24, Vcc = 3.3 V)
(1)
Temperature Phase Noise Change in Celsius for Various Offsets
Lock Current 10 kHz 100 kHz 1 MHz 10 MHz 20 MHz
-40 -40 +0.4 -2.0 -1.6 -1.8 -1.6
-40 25 +0.3 +0.5 +0.5 +0.5 +0.4
-40 85 +0.9 +2.0 +2.4 +2.5 +2.3
25 -40 +0.2 -2.2 -1.7 -2.0 -1.8
25 25 This is the default condition to which these other numbers are normalized to.
25 85 +0.6 +1.5 +2.0 +2.0 +1.9
85 -40 +0.2 -2.2 -1.7 -1.9 -1.8
85 25 +0.2 +0.2 +0.3 +0.2 +0.2
85 85 +0.6 +1.8 +2.2 +2.3 +2.1
(1) The table shows the typical degradation for VCO phase noise when the VCO is locked at one temperature and the temperature is
allowed to drift to another temperature. A negative value indicates a phase noise improvement.
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LMX2541SQ3320E LMX2541SQ3740E